84 



CHRYSOLITE. 



■tvhite. Transparent. Fracture conchoidal. 

 H. 6-5 to 7. S.G. 3 3514 to 3-44L 



Fig. 116. 



Comp. R3 Si in which 11 may be Mg Fe 



Mn Ca alone or in combination. 



Analysis by Stromeyer (Oriental Chry- 

 solite) : 



Silica ..... 39-73 

 Magnesia .... 50-13 

 Protoxide of iron . . 9-19 



Alumina .... 0-22 

 Protoxide of manganese . 009 

 Oxide of nickel . . . 0-32 



99-68 



Localities. Chrysolite occurs near Con- 

 stantinople, at Vesxxvius, and the Isle of 

 Bourbon, in lava. Imbedded in Obsidian at 

 Real del IMonte, in Mexico. In pale green 

 transparent crystals among sand at Expailly, 

 in Auvergne. It is also found in Upper 

 Egvpt. 



It is usually found in angular or rolled 

 pieces, rarely crystallized. The crj'Stals 

 (usually 8, 10, or 12-sided prisms) are vari- 

 ously terminated, and often so compressed 

 as to become almost tabular. They are 

 generally very fragile, and therefore unfit 

 for ornamental stones. 



As a gem, the Chr3'solite is deficient in 

 hardness and play of colours, but when the 

 stones are large, of good colour, and well 

 matched, free from flaws, and well cut and 

 polished, it is made into necklaces, hair- 

 ornaments. &c., with good effect. From its 

 softness, which is not much greater than 

 that of glass, it requires to be Avorn with 

 cai-e, or it will lose its polish, and wear off" 

 at the edges. The best mode of displaying 

 the colours to the greatest advantage is to 

 cut it in small steps. To give it the highest 

 polish, a copper wheel is used, on which a 

 a little sulphuric acid is dropped.' During 

 the process, a highly suffocating smell is 

 given out, produced probably by the action 

 of the acid on the copper and the gem. 



The Chrysolite or Peridot has been con- 

 founded not only with the Chrysoberyl but 

 with the greenish-yellow varieties botii of 

 Sapphire, Topaz, Aquamarine, and even of 

 Apatite and Idocrase. It is softer than 

 Chrysoberyl, Sapphire, Topaz, or Aquama- 



CHRYSOPRASE. 



rine, but harder and heavier than Apatite, 

 while its infusibility and non-electrical pro- 

 perties, when heated, distinguish it from 

 green Tourmaline. 



The Chrysolite is supposed to have been 

 the Topaz of the ancients. 



The name is derived from %?y<ro?, gold, and 

 A/6o?, stone, in allusion to its colour. 



Brit. Mus., Case 25. 



31. P. G. Horse-shoe Case, Nos. 925 to 

 928. 



Chrysolite co^imune. See Olivine. 



Chrysolite du Cap. See PREH^^ITE. 



Chrysophane, Breithdupt. A name given 

 to Holmesite or Clintonite, the composition 

 of which may be represented by the formula 



2(Al Mg) + Ca Si + H. 

 Analysis by Richardson : 



Silica 19 35 



Alumina . . • . . 44-75 

 Magnesia .... 9*05 



Lime 11-45 



Peroxide of iron . . . 4-80 

 Protoxide of manganese . 1'35 

 Zirconia .... 2*05 

 Fluorine .... 0-90 

 Water . . . .4-55 



98-25 



Name. From xi'^'^'^^, gold, and 'falvai, to 

 seem. 



Chrysoprase (from %§y«-o?, gold, and 

 ^^xirov, a leek), an apple-green or leek-green 

 variety of Chalcedony, passing into Horn- 

 stone find Chalcedony, and differing from 

 the latter, apparent!}', in little more than 

 colour. It occurs massive, in thick plates; 

 never crystallized. Fracture even, or 

 finely splintery, or flat-conchoidal, with a 

 slight degree of lustre. H. slightly less than 

 that of Quartz. 



Analysis by Klaproth : 



Silica ..... 96-16 

 Oxide of nickel . . . 1-00 

 Lime . . . . .0-83 



97-99 

 This stone is not hdd in much esteem as 

 an article of jewelry in this country, but on 

 the continent it is more highly valued, and 

 is made into brooches, rings, bracelets, seals, 

 •&c., the larger pieces being converted into 

 snuff-boxes, cane-heads, &c. The apple- 

 green variety is the most valuable. It should 

 be cut en cabochon, as it is spoiled if cut in 

 facets, and appears to most advantage by 

 candle-light. Chrysoprase is apt to lose its 

 colour and to become dark and clouded if kept 



